At about 22:45 Eastern Daylight Time (EDT) on 05 July 2013, Montreal Maine & Atlantic (MMA) freight train MMA 2 (the train) was proceeding eastward on the MMA Sherbrooke Subdivision, enroute from Montreal (QC) towards Saint John (NB). The train was 4701 feet long and weighed 10,287 tons. It was comprised of 5 head-end locomotives, a VB car used to house the locotrol equipment necessary for MMA’s single engineer train operation, 1 loaded box car used as a buffer followed by 72 non-pressure dangerous goods tank cars loaded with petroleum crude oil (Class 3, UN 1267).

At approximately 23:00, the train stopped at the designated MMA crew change point at Mile 7.40 near Nantes, Quebec. The single operator secured the train and departed for the evening leaving the lead locomotive unlocked and the train unattended on mainline track with a descending grade of 1.2%.

At about 23:50, a local resident reported a fire on the lead locomotive (MMA 5017) to the 911 emergency call centre. Subsequently the local fire department responded along with another MMA employee. At about midnight, similar with established operating practice, emergency shutdown procedures were initiated on the lead locomotive and the fire was extinguished. After extinguishing the fire, the second MMA employee and the fire department departed the site again leaving the train unattended.

Shortly before 01:00 on 06 July 2013, the train started to move and gathered speed as it rolled uncontrolled down the descending grade into the town of Lac-Mégantic, Quebec, 7.4 miles southeast of Nantes. While travelling at well in excess of the authorized speed, the train derailed near the centre of Lac-Mégantic. The locomotives separated from the train and came to a stop about ½ mile east of the derailment. The derailed equipment included the box car (buffer) and 63 tank cars.

Several derailed tank cars released product resulting in multiple explosions and subsequent fires causing an estimated 42 fatalities and 8 persons still missing, extensive damage to the town centre and precipitated the evacuation of about 2000 people from the surrounding area (TSB Occurrence No. R13D0054).

The ongoing investigation has determined that the braking force applied was insufficient to hold the train on the 1.2% descending slope between Nantes and Lac-Mégantic.

Over the years, the TSB has investigated a number of similar runaway accidents (see Appendix A). Each of these investigations brings into question the effectiveness of the Transport Canada (TC) approved Canadian Rail Operating Rules (CROR) Rule 112 entitled “Securing Equipment” and the standard railway operating procedures and practices utilized for performing that task.

Specifically CROR Rule 112 states:

“When equipment is left at any point a sufficient number of hand brakes must be applied to prevent it from moving. Special instructions will indicate the minimum hand brake requirements for all locations where equipment is left. If equipment is left on a siding, it must be coupled to other equipment if any on such track unless it is necessary to provide separation at a public crossing at grade or elsewhere.

Before relying on the retarding force of the hand brake(s), whether leaving equipment or riding equipment to rest, the effectiveness of the hand brake(s) must be tested by fully applying the hand brake(s) and moving the cut of cars slightly to ensure sufficient retarding force is present to prevent the equipment from moving. When leaving a cut of cars secured, and after completion of this test, the cut should be observed while pulling away to ensure slack action has settled and that the cars remain in place.

Application of hand brakes must not be made while equipment is being pulled or shoved.”

Trains are required to be secured in accordance with CROR Rule 112 in addition to any related railway company special instructions which vary from company to company. While most railway special instructions specify the minimum number of hand brakes needed in general operating conditions, they do not always provide the number of hand brakes required under specific conditions. In many cases, it is left up to the operating employee to determine the number of hand brakes to apply. The employee must take into consideration the slope or grade of the track and the approximate tonnage of the equipment to be secured at that location.

In addition, TSB investigation R96C0172 previously established that that there was considerable variability in the effectiveness of the hand brake system on railway cars. The variability was associated with the design, condition and maintenance of the hand brake system, as well as with differences among operators with respect to their physical capabilities and personal technique used to apply the hand brakes. Specifically, the torque applied by the operating employee may not be proportional to the effective brake shoe force actually applied. In other words, high torque does not necessarily generate a high braking force. This variability was not widely understood at the time of the investigation and could still present a risk particularly with new employees.

More recently, to add to the complexity, TSB investigation R12E0004 identified that the push –pull test used by railways to satisfy CROR Rule 112 (b) does not always adequately verify if the braking force of the hand brake application was sufficient to hold the cars.

CROR Rule 112 ensures that hand brakes are applied to prevent unwanted movement of the train while providing flexibility for a railway’s operational needs. However, CROR Rule 112 is not specific enough in that it does not indicate the number of hand brakes necessary to hold a given train tonnage on various grades and it continues to be left up to the operating employee to determine the number of hand brakes to apply. Furthermore, it has been demonstrated that the push–pull test is not always a good indicator of whether an adequate number of hand brakes have been applied and not all handbrakes are effective even when properly applied. Considering all these risks, Transport Canada may wish to review CROR Rule 112 and all related railway special instructions to ensure that equipment and trains left unattended are properly secured in order to prevent unintended movements.

Appendix A

Over the years, the TSB has investigated a number of similar runaway accidents. A summary of several of the more significant accidents is appended below:

R96C0172 (Edson) - On 12 August 1996, all 3 three occupants in the operating cab of the lead locomotive of Canadian National (CN) westward freight train No. 117 were fatally injured when their train, which was travelling at about 54 mph, collided head-on with a cut of 20 runaway cars moving eastward at about 30 mph, some six miles east of Edson, Alberta. The runaway cars had been left on a track in Edson Yard by a crew who had applied hand brakes to 2 covered hopper cars. The crew had little supervision to ensure that the company's car securement procedures were being correctly applied. The performance of the hand brakes on that type of car was found to be highly variable, and the variability was not commonly known amongst operating employees. Although the crew thought the cars had been secured, the resultant brake shoe force on the two cars was insufficient to prevent movement. Thus, the cut of 20 cars slowly moved east and accelerated toward the main track.

R09T0057 (Nanticoke) – On 11 February 2009 at 2118 Eastern Standard Time, the Southern Ontario Railway 0900 Hagersville Switcher, consisting of 4 locomotives and 43 cars, ran uncontrolled from Mile 0.10 to Mile 1.9 of the Hydro Spur track. The train reached a speed of 20.7 mph before travelling over a split switch derail and derailing 9 loaded dangerous goods tank cars. Three tank cars loaded with gasoline (UN 1203) were breached and released approximately 31 000 litres of gasoline. Two nearby homes were evacuated; there were no injuries.

The investigation determined that the accident occurred when the crew left the train unattended on a one per cent descending grade, without the train being properly secured. Subsequently, the train rolled uncontrolled downgrade for 1.4 miles, across an unprotected crossing, reaching a speed of 20.7 mph before it encountered a split switch derail and derailed the nine tail-end cars. With only one crew member left at the end of the shift, the other crew members did not have an opportunity to verify whether the train was properly secured.

R11Q0056 (Doree) – On 11 December 2011, as freight train LIM-55 was descending a long steep grade, the locomotive engineer, unable to control the train speed using the dynamic and automatic brakes, applied the emergency brakes at Mile 68.00 of the Wacouna Subdivision to stop his movement. One hour later, the train ran away, descending the grade for a distance of almost 15 miles and reaching a maximum speed of 63 mph. The train finally came to a stop at Mile 52.80. No one was injured and there was no derailment.

The investigation determined that 1 hour after the emergency brakes were applied and the train came to a stop, the air brakes released and, because the braking force applied by the hand brakes was insufficient, the train ran away. Without specific instructions that take into consideration local conditions, there is a risk of underestimating the number of hand brakes required to secure a train on a steep grade and preventing it from running away.

R12E0004 (Hanlon) – On 18 January 2012, at 1212 Mountain Standard Time, 13 loaded coal cars, which were running uncontrolled northward from the Hanlon siding, Mile 41.7 on the Grande Cache Subdivision, collided with stationary train A45951-16 at Mile 44.5. Nine of the 13 cars and the 3 leading locomotives from the train derailed. Two crew members sustained minor injuries and were treated on site. The 3rd crew member was seriously injured and was air lifted to hospital in Hinton, Alberta. Approximately 2800 litres of fuel and 740 tons of coal were spilled. About 250 feet of track was damaged.

The investigation determined that the conductor's belief that the cars were on level ground likely led to the conclusion that 1 hand brake was sufficient to secure the cut of cars. When the braking force from the train brakes was sufficiently reduced due to bleeding off of the air in the cars' brake cylinders, the retarding force of the 1 applied hand brake could not resist the gravitational force of the 13 loaded coal cars. In addition, because the brake effectiveness test was conducted by attempting to push the cars upgrade, it did not adequately verify if the braking force of the hand brake application was sufficient to hold the cars.